PROVIDE NESTING BOXES 39 
ficial and should be protected. If farm buildings 
have sufficiently large openings, the barn owl will enter 
and look after the mice. I suggest that experiments be 
made with nesting boxes for them. The boxes should 
vary in size from 16x 12x 12 to 18x14x 14. Use 
some with large side opening and leave the others en- 
tirely open at the top and observe the results. The 
boxes should be fastened in crotches of trees. Bore a 
few small holes into the bottom of the open boxes, so 
that rain water will not accumulate in them. 
9. The Wood Duck. —This most beautiful and inter- 
esting of all ducks has much decreased in Minnesota, 
and no doubt in all settled districts. Even where the 
lakes still ripple and plash in the June breeze, its 
natural homes, the old and hollow trees, are gone. The 
farmers have cut them for fuel, or some individual, who 
styles himself hunter or trapper, has burned and cut the 
hoary sires of the primeval forest, because a poor squir- 
rel, or a cottontail, or even a coon had taken refuge in 
them. 
Boxes having the natural bark on them, will un- 
doubtedly attract the wood duck. Make the boxes about 
24 x 16 x 16 to 86 x 18 x 18. They may be provided 
with side openings of 4 to 5 inches diameter, or the top 
may be left open. According to Masefield, an English 
writer, such boxes have long been used in Lapland. 
Place the boxes on trees in well-wooded places near 
rivers and lakes. Wood ducks frequently build in 
convenient crotches and on stumps. I would, therefore, 
suggest that some very shallow boxes be also used. 
